Design process
Clear aligner design is divided into 3 stages: Segmentation > Setup > Modeler.
Segmentation
This is the process of separating teeth and gums.
We provide know-how to maintain the shape of the patient's teeth.
When segmenting only partial teeth(eg, want to setup only anterior, etc.)
Since a non-segmented tooth is recognized as a gum, it is segmented by +1 compared to the tooth to be moved to prevent morphing.
Setup
This is the process of moving teeth arbitrarily to make clear aligner.
Space
Because the teeth do not move when contact occurs between teeth, to prevent contact, there must be space for the teeth to move.
How to make space
Expansion
Depending on the tooth crowding, expansion through the whole movement including the tooth root, or through torque adjustment.
#11-21 0.30mm, #13-14 0.3mm, #23-24 0.30mm IPR
IPR
After final setup by distributing the overlap amount evenly, note the teeth and amount to be IPR.
Recommended IPR
The minimum thickness of enamel layer is usually 1mm, and half can be removed.
| Tooth no. (FDI) | 11 | 12 | 13 | 14 | 15 | 16 |
|---|---|---|---|---|---|---|
| IPR (mm) | 0.5 | 0.3 | 0.5 | 0.5 | 0.5 | 0.5 |
| Tooth no. (FDI) | 41 | 42 | 43 | 44 | 45 | 46 |
|---|---|---|---|---|---|---|
| IPR (mm) | 0.3 | 0.3 | 0.5 | 0.5 | 0.5 | 0.5 |
Layer
If you setup without a layer, it will interfere with adjacent teeth, so you must use and setup with a layer.
Setup protocol: Expansion > Alignment > Retraction
Overcorrection
Due to the physical characteristics of clear aligner, overcorrection is required because the teeth do not move to the target position due to the deformation of the device. Overcorrection more than the target position within 0.1 mm of overlap or 0.2mm of movement.
How to select the sheet
Depending on the sheet, it can be changed how to divide the layers.
| Sheet Usage Examples | ||
|---|---|---|
| Standard Sheet | 3-Layer Sheet | |
| Medium (1 week) + Hard (1 week) (2 weeks per stage) | Soft (1 week) + Medium (1 week) + Hard (1 week) (3 weeks per stage) | Hard sheet (10–14 days per stage) |
| 0.4–0.6 mm of tooth movement per stage | 0.6–1.0 mm of tooth movement per stage | 0.25–0.3 mm of tooth movement per stage |
| Desired treatment outcomes can be achieved with fewer stages, resulting in higher satisfaction for both clinicians and patients. | Allows greater tooth movement per stage. | Provides stable tooth movement with smaller increments. |
| Item | Standard Sheet | 3-Layer Sheet |
|---|---|---|
| Structure | Single-layer PETG material | Sandwich structure with rigid outer layers and an elastic inner layer |
| Orthodontic Force | Orthodontic force decreases significantly over time | The elastic inner layer allows a more gradual decrease in orthodontic force and helps maintain force over time |
| Comfort | Lower elasticity may cause discomfort or a stronger sense of pressure | Superior elasticity provides better comfort during wear |
| Durability | Relatively higher risk of deformation and cracking | The elastic inner layer provides excellent shape recovery and greater durability |
| Cost | Relatively inexpensive | Relatively expensive |
| Available Thicknesses | Soft - 0.5 mm (0.02 inch) Medium - 0.625 mm (0.025 inch) Hard - 0.75 mm (0.03 inch) | Hard - 0.75 mm (0.03 inch) |
How to set step
How to calculate the total treatment period
Total number of steps
(If the number of upper and lower steps is different, it is based on the long step)
x Weeks per step according to sheet selection